Rotary engine with radially shiftable rotor

ABSTRACT

A rotary engine including a hollow housing having an irregular but generally cylindrical cavity therein and a shaft journalled through the cavity in off-center relation thereto. The curved walls of the housing defining and extending about the cavity gradually increase and decrease in radial distance from the axis of rotation of the shaft but the spacing between all working curved wall portions of the cavity lying at opposite ends of all diameters of the aforementioned axis is constant. An elliptical rotor is mounted on the shaft within the cavity for rotation with the shaft and for shifting radially of the axis of rotation of the shaft along a line extending between the vertices of the rotor while fuel mixture and exhaust by-products inlet and outlet means and fuel mixture ignition means are spaced about the outer periphery of the cavity. Also, the rotor and shaft define a rotary assembly having axially extending air passages extending therethrough opening through opposite ends of the housing with air vane structure carried by one end of the rotary assembly operative to pump cooling air through the air passages in response to rotation of the assembly.

United States Patent Dieter [54] ROTARY ENGINE WITH RADIALLY SHIFTABLE ROTOR [72] Inventor: Robert L. Dieter, 919 Cliffwood Drive, Mt. Pleasant, SC. 29464 [22] Filed: Feb. 10, 1970 [21] App1.No.: 9,473

[52] US. Cl. ..4l8/6l, 4l8/91, 418/101, 418/119, 123/845 [51] Int. Cl. ..F03c 3/00, F02b 55/14, FOlc 19/02 [58] Field of Search........418/54, 61, 88, 91, 94,101, 418/117, 253, 255, 257, 269, 119; 123/845 [56] References Cited UNITED STATES PATENTS R22,160 8/1942 Davis ..4l8/255 553,086 1/1896 Wheildon ..418/54 983,033 1/1911 Elliott .......4l8/253 1,116,471 11/1914 Neumeyer... ..418/101 1,277,018 8/1918 Wolfingtoml ..4l8/6l 1,310,157 7/1919 De Campo ..418/54 1,802,887 I 4/1931 Feyens ..4l8/54 3,369,529 2/1968 Jordan ..4l8/101 3,480,203 11/1969 Koch ..418/54 [451 Sept. 12, 1972 Primary Examiner-Carlton R. Croyle Assistant Examiner-John J. Vrablik Attorney-Morgan, Finnegan, Durham 8!. Pine [5 7] ABSTRACT A rotary engine including a hollow housing having an irregular but generally cylindrical cavity therein and a shaft journalled through the cavity in off-center relation thereto. The curved walls of the housing defining and extending about the cavity gradually increase and decrease in radial distance from the axis of rotation of the shaft but the spacing between all working curved wall portions of the cavity lying at opposite ends of all diameters of the aforementioned axis is constant. An elliptical rotor is mounted on the shaft within the cavity for rotation with the shaft and for shifting radially of the axis of rotation of the shaft along a line extending between the vertices of the rotor while fuel mixture and exhaust by-products inlet and outlet means and fuel mixture ignition means are spaced about the outer periphery of the cavity. Also, the rotor and shaft define a rotary assembly having axially extending air passages extending therethrough opening through opposite ends of the housing with air vane structure carried by one end of the rotary assembly operative to pump cooling air through the air passages in response to rotation of the assembly.

11 Claims, 11 Drawing Figures Patented Sept. 12,1972 1 3,690,791

3 Sheets-Sheet 2 40 Robert L .Diefer INVENTOR.

WITH RADIALLY SHIFIABLE ROTOR ROTARY ENGINE The rotary engine has been designed to provide a means whereby an efficient power source may be had and specifically adapted for use in a particular environment. The engine includes three principle elements including a housing defining a combustion chamber, a rotor and a rotor shaft upon which the rotor is mounted for rotation therewith and shifting axially of the shaft. The rotor is generally elliptical in shape and is mounted for rectilinear shifting relative to the rotor along a plane passing through the vertices of the rotor.

The engine illustrated anddescribed hereinafter is naturally aspirated and includes poppet-type intake and exhaust valves as well as magneto ignition. The intake and exhaust valves as well as the magneto are disposed at one end of the engine and accordingly, the operation of the engine may be modified'by exchanging one housing end wall for another including different valve operation, air and fuel induction features and ignition components. Further, the central portion of the housing defining the cavity in which the rotor is disposed may also be substituted for by a housing portion defining a slightly different shaped cavity to further modify the operation of the engine, and the rotor itself may also be exchanged by a rotor of slightly different configuration as a means for modifying the operation of the engine. All of these substitutions may be readily carried out with little down time of the engine involved and accordingly, an extremely versatile engine capable of utilizing various fuels is provided.

Further, the spark plug or other ignition means for igniting compressed air and fuel mixtures within the engine may be located in either end wall of the cavity in which the rotor is received or along any side wall of the cavity in a position which may prove to be most advantageous when utilizing a particular engine configuration and fuel.

In addition to the aforementioned desirable structural and operational features of the engine, the exterior surfaces of the portion of the housing defining the rotor cavity may be provided with air cooling fins and exterior air turbine means may be provided and driven by the rotor shaft for forcing cooling air over the exterior surfaces of the engine. Further, the engine is provided with interior axially extending cooling air passages which extend through the rotor shaft and rotor and means is provided for pumping air through the interior cooling passages in response to rotation of the rotor shaft.

The main object of this invention is to provide a rotary engine including structural components which may be readily substituted for or otherwise readily modified in a manner to vary the operating characteristics of the engine as desired in accordance with a particular environment in which it is to be used and fuel to be used in conjunction therewith.

A still further object of this invention is to provide a rotary engine readily adaptable to exterior cooling by air and also including eflicient internal air cooling passages through which cooling air is automatically pumped upon rotation of the rotor shaft of the engine.

Another object of this invention is to provide a rotary engine including but a few major components which each may be substituted for by a similar but slightly different component with a minimum of down time of the engine in order to modify the operating characteristics of the engine.

A final object of this invention to be specifically enumerated herein is to provide a rotary engine which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a longitudinal sectional view taken substantially upon a plane disposed along a diameter of the axis of rotation of the rotor shaft of the engine and extending through the centers of the intake and exhaust ports of the engine;

FIG. 2 is a top plan view of the engine;

FIG. 3 is a bottom plan view of the engine;

FIGS. 4 through 7 are transverse sectional views taken substantially upon the plane indicated by the section line 4-4 of FIG. 1 and with the rotor and rotor shaft portions of the engine in variously relatively angularly displaced positions;

FIG. 8 is a fragmentary side elevational view of the cam disk portion of the rotor shaft;

FIG. 9 is a fragmentary exploded perspective view of the rotor and ring assembly of the engine;

FIG. 10 is a fragmentary enlarged sectional view illustrating the manner in which the sealing ring strips disposed on opposite sides of the plane upon which FIG. 1 is taken are interlockingly engaged with each other; and

FIG. 11 is a fragmentary perspective view of the contact points system by which the electrical current from the magneto is supplied to the spark plug in timed sequence.

Referring now more specifically to the drawings the numeral 10 generally designates the rotary engine of the instant invention. The engine 10 includes a housing 12 including a stationary end wall 14 and a removable end wall 16. Although the end wall 14 is illustrated as stationary, it may be readily constructed as a separate piece removably secured to the main body portion 18 of the casing 12 which defines a rotor cavity 20 that is generally cylindrical.

The end wall 14 and 16 have corresponding slightly offset openings 22 and 24 formed therein in which combined thrust and journal bearing assemblies 26 and 28 are disposed. Diametrically enlarged opposite end portions 30 and 32 are journalled through the bearing assemblies 26 and 28. In addition, the end portion 30 has a pair of small inlet bores 36 fonned therethrough and the end portion 32 has a pair of small outlet bores 38 formed therethrough.

That portion of the rotor shaft 34 disposed between the end portions 30 and 32 is rectangular in cross-sectional shape and a rotor referred to in general by the reference numeral 40 is provided and includes an axial slot 42. The rotor 40 is generally elliptical and the medial plane of the slot 42 coincides with a plane passing through the vertices of the rotor 40. The rectangular central portion 44 of the shaft 34 between the end portions 30 and 32 is slidingly received in the slot 42 and accordingly, the rotor 40 is rectilinearly reciprocal relative to the central portion 40 in the medial plane of the slot 42.

The rotor 40 further includes seal strip grooves 46, 48 and 50 and a pair of U-shaped seal strips 52 and 54 are interlockingly engaged with each other and received in the grooves 46 while a similar pair of seal strips 56 and 58 are interlockingly engaged with each other and received in the grooves 48. In addition, a third set of seal strips 60 and 62 are interlockingly engaged in the grooves 50 which lie in the aforementioned medial plane of the slot 42. As can best be seen from FIG. 1 of the drawings the seal strips 60 and 62 may have their opposing end portions flexed apart so that the projections 64 thereof may be interlockingly engaged behind the shoulders 66 on the rotor 40 defined by the grooves 50. Further, from FIG. of the drawings it may be seen that each pair of corresponding seal strips 52 and 54 as well as the seal strips 56 and 58 may have their corresponding end portions interlockingly engaged with each other so as to thus lock the seal strips 52, 54, S6 and 58 to the rotor 40.

The end wall 16 is removably secured to the body portion 18 of the housing 12 by means of removable fasteners 68 and a cooling air outlet manifold 70 is mounted on the exterior face of the end wall 16 and includes an air outlet duct 72 whose inlet end opens into the outlet manifold 70. Further, the end portion 30 includes air vanes 74 operatively associated with each of the passages or bores 36 whereby rotation of the rotor 40 and rotor shaft 34 in a counterclockwise direction as viewed in FIGS. 4-7 of the drawings will cause cooling air to be pumped into the slot 42 through the bores 36 and then out of the slot 42 through the bores 38 and into the outlet manifold 70.

The end wall 16 includes an exhaust port 78 and an intake port 80. An exhaust manifold 82 is operatively associated with the exhaust port 78 and an intake manifold 84 is operatively associated with the intake port 80. Further, a spring seated poppet-type exhaust valve 86 is reciprocally mounted from the exhaust manifold 82 for opening and closing the exhaust port 78 and a similar intake valve 88 is reciprocally mounted from the intake manifold 84 for opening and closing the intake port 80.

The exhaust port 86 defines a valve seat 90 with which the head portion of the valve 86 coacts and the intake port 80 defines a seat 92 with which the head portion of the valve 88 coacts. However, the seats 90 and 92 are recessed within the ends of the ports 78 remote from the chamber in which the rotor 40 is disposed.

If it is desired, any suitable carburetor or fuel injection system may be operatively associated with the intake port 84 and the air and fuel mixture may be admitted into the intake port 80 by natural aspiration or a supercharging structure (not shown) driven from the rotor shaft 34 may be provided for forcing air and fuel mixture through the intake manifold and the port 80 whenever the valve 88 is open.

A pair of rocker arms 96 and 98 are oscillatably supported from the air outlet manifold 70 as at 100 and 102 and the remote ends of the rocker arms 96 and 98 include one-way connections with the upper ends of the exhaust and intake valves 86 and 88. The adjacent ends of the rocker arms 96 and 98 define followers guidingly engaged in a double-convolution endless groove 104 formed in a cam body 106 removably mounted on the upper end of the rotor shaft 34 in any convenient manner (not shown). Further, the outlet manifold includes an upper wall 108 through which the portion of the rotor shaft 34 disposed immediately beneath the cam body 106 is rotatably joumalled.

A magneto rotor 110 is mounted on the upper end of the rotor shaft 34 above the cam body 106 and is thus rotatable relative to a magneto stator portion (not shown) supported from an end wall cover 112 which may be removably secured to the end wall 16 in any convenient manner (not shown).

With attention now invited more specifically to FIGS. 2 and 11, a guide structure 114 is supported from the end wall 16 in any convenient manner for reception within the cover 112 and the guide structure 114 includes a reciprocal follower 116 guidingly supported therefrom including an outwardly projecting follower element 118 whose outer end is also guidingly received in the double convolution groove 104 formed in the cam body 106. Accordingly, the follower 116 is reciprocated vertically upon rotation of the rotor shaft 34 and the cam body 106. The follower 116 also includes an outwardly extending point contact actuating arm 120 which is positioned relative to flexible contact elements 122 and 124 of a pair of vertically spaced sets of contact elements for downward and upward deflection of the elements 122 and 124 relative to the stationary elements 126 and 128 upon vertical reciprocation of the arm 120. The sets of contact elements are mounted on a support plate 130 which is secured to the guide structure 114 to an adjustable vertical shifting by means of fasteners 132. In addition, suitable conductor means (not shown) extend from the stationary magneto component to the elements 122 and 124 and the contact elements 126 and 128 are electrically connected to a spark plug 134 by means of a conductor 136. Accordingly, downward movement of the dielectric arm 120 from the position thereof illustrated in FIG. 11 of the drawings will cause the contact element 122 to first contact the element 126 and then the contact element 124 to contact the contact element 128. As each element 126 and 128 is contacted by the corresponding element 122 and 124, the stationary component of the magneto is electrically connected to the spark plug 134 through the conductor 136 and thus an electrical spark is caused to jump the gap (not shown) between the electrodes of the spark plug 134 with this spark communicated with the chamber 20.

With attention now invited more specifically to FIGS. 4 through 7 of the drawings, four progressive rotated positions of the rotor 40 may be seen. Inasmuch as the rotor has constant dimensions, in order that the vertices thereof be maintained in close sliding engagement with the walls of the cavity 20, all transverse dimensions of the cavity 20 taken through the center of the central portion 44 of the rotor shaft 34 are constant, even though the walls of the cavity 20 are not perfectly cylindrical. This enables the rotor 40 to operate through successive intake, compression, power and exhaust strokes in relation to the exhaust and intake ports 78 and 80 and the spark plug 134. Accordingly, the rotor 40 is positioned in the full compression position in FIG. 4 of the drawings, at the beginning of the power stroke in FIG. 5 of the drawings, partially through the power stroke in FIG. 6 of the drawings and at a position approaching the end of the power stroke in FIG. 7 of the drawings. However, these positions are only in relation to that side of the rotor 40 which opposes the spark plug 134 in FIG. 4 of the drawings. That side of the rotor 40- facing away from the spark plug 134 in FIG. 4 is disposed at the end of a power stroke while FIGS. 5 through 7 illustrate that side of the rotor 40 at the beginning of the exhaust stroke, mid-way through the exhaust stroke, and at the end of the exhaust stroke.

Thus, an illustrative operation of the engine through two complete revolutions in 90 segments (or onequarter of a revolution) is as follows, and for this purpose FIGS. 4 and 6 may be referred to alternately.

State 1. (FIG. 4 START). The combustion mixture is compressed in the upper area of the combustion chamber. The lower area contains an uncompressed mixture previously admitted. The intake valve 88 has just closed since the intake valve cam follower 98 has moved into the lower section of track 104 in cam 106. The exhaust valve 86 is also in its closed position (having closed 180 earlier). The ignition cam follower 116 which has also started to descend causes the upper contact points 122, 126 to close which in turn causes ignition in the combustion chamber.

Stage 2. (FIG. 6 One-Quarter Revolution). The expanding, burning gases in the left lobe force the rotor around in a counter-clockwise direction compressing the unignited mixture in the right lobe. The intake valve cam follower 98 is now all the way down in the lower section of track 104 and the intake valve 88 remains closed. The exhaust valve cam follower 96 has reached a point at which it will start to rise (but the valve will still remain closed for 90 more of a revolution). The ignition cam follower 116 is at mid-point in its descent.

Stage 3. (FIG. 4 One-Half Revolution). The combustion gases have now expanded to approximately their maximum volume in the lower chamber, while the combustion mixture in the upper chamber is at approximate maximum pressure and minimum volume. At approximately this point, ignition again occurs in the upper chamber since the ignition cam follower 116 has now reached its lowest point and the lower contact points 124, 128 are depressed. The exhaust cam follower 96 has now reached the mid-point in its rise and the exhaust valve 86 now opens. The intake valve follower 98 is still in the lower section of track 1'04 so the intake valve 88 remains closed.

Stage 4. (FIG. 6 Three-Quarter Revolution). Expanding, combusting gases in the left lobe force the rotor to continue to revolve and force the previously combusted gases in the right lobe out through the exhaust port 86 which was opened in the previous stage. The intake valve cam follower 98 is still in the lower section of track 104 so intake valve 88 remains closed. The ignition cam follower 116 is also in the lower section of track 104. r

Stage 5. (FIG. 4 One Revolution). The combustion gases are now reaching their approximate maximum volume in the lower chamber, while the burned gases in the upper chamber have been largely exhausted through the open exhaust port 86. The intake valve 88 now has started to open since its follower 98 has entered the upper section of track 104. The ignition cam follower 116 is still in the lower section of track 104.

Stage 6. (FIG. 6 One and One-Quarter Revolution). A fresh combustion mixture is inducted through the open port 88 in the left lobe. The previously combusted mixture in the right lobe is exhausting through the open exhaust port 86 which remains open since the exhaust valve cam follower 96 is in the upper section of track 104. The ignition cam follower 116 has started to rise and is approximately at mid-point.

Stage 7. (FIG. 4 One and One-Half Revolution). The previously burned gases are now largely exhausted from the upper chamber and the exhaust valve 86 is closing since its cam follower 96 is entering the lower section of cam track 104. The lower chamber contains approximately its maximum volume of uncompressed combustible mixture. The ignition follower 1 16 is in the upper section of track 104. The inlet valve 88 remains open.

Stage 8. (FIG. 6 One and Three-Quarter Revolution). A fresh combustion mixture is inducted through the open inlet port 88 in the left lobe and compression of the mixture in the right lobe is underway. The exhaust valve 86 is closed, the intake valve cam follower 98 has started to descend and the ignition cam follower 116 will start its descent in the next phase, whereupon the cycle is repeated.

It will be seen from the foregoing that there are two combustion episodes occurring or one-half revolution, apart during two complete revolutions of the rotor and, consequently, that the engine 10 endures two power strokes for every two revolutions of the rotor 40.

As previously hereinbefore set forth, the housing 12 may be externally cooled and the rotor 40 is internally cooled by means of the bores 36 and 38 and the slot 42. Also, the magneto may be replaced by a conventional distributor and the proper air and fuel mixture may be supplied to the intake manifold 84 by means of a naturally aspirated carburetor, a carburetor to which air under pressure is supplied by means of a supercharger or by a naturally aspirated air intake into which correct portions of fuel is injected. Also, by varying the shape of the chamber and/or the rotor 40 the effective compression ratio of the engine 10 may be modified as desired and the ignition timing may be varied by adjustment of the support portion on the plate 130.

It is proposed that sufficient lubrication of the internal components of the engine 10 may be accomplished by utilization of an air and fuel mixture including lubricating oil such as is the practice in conventional reciprocating piston two-cycle engines. Further, cooling of the engine 10 could be accomplished by liquid wherein the housing 12 would be provided with an external water jacket through which cooling water or other cooling fluids could be pumped. Further, a plurality of the engines 10 could be mounted in tandem fashion on a single rotary output shaft if the magneto end of the shaft 34 of the engine 10 was extended through the magneto stator portion. Of course, if this type of tandem engine was provided, the magneto stator portion would have to be modified so as to receive a shaft portion therethrough.

The forgoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. Rotary internal combustion engine including, a hollow housing defining an irregular, generally cylindrically-shaped rotor cavity;

a shaft removably joumalled for rotation in said housing and extending through said cavity in fixed, offset relation relative to the center of said cavity;

said cavity having transverse dimensions which are substantially equal measured along all straight lines extending through the axis of rotation of said shaft;

a generally elliptical rotor of fixed transverse dimensions removably mounted on said shaft for direct rotation therewith and also for rectilinear shifting relative to said shaft within said cavity in a plane extending generally through the vertices of said rotor and the axis of rotation of said shaft, the length of said rotor along said plane extending through said vertices thereof being approximately equal to the transverse dimension of said cavity measured through the axis of rotation of said shaft;

said shaft mounting said rotor within said cavity so that the opposed surfaces of said rotor extending between the vertices thereof and the irregular shape of the cavity wall continuously define both compression and expansion compartments of predetermined volume varying between minimum and maximum volumes and having a predetermined volumetric relationship to each other;

valved inlet and exhaust port means opening into said cavity for introducing a suitable mixture of air and combustible fuel to said cavity and exhausting said mixture and combustion by-products therefrom after combustion, respectively; and

ignition means mounted in said housing at a point where said compression compartment has its minimum volume, said ignition means creating an electrical spark which is communicated to said cavity for igniting the compressed air and fuel mixture.

2. A rotary internal combustion engine as claimed in claim 1, wherein said rotor includes a slot extending axially thereof and through which said shaft extends, the medial plane of said slot lying generally upon a line extending between the vertices of said rotor, whereby said rotor is shiftable relative to said shaft in said plane generally radially of the axis of rotation of said shaft.

3. A rotary internal combustion engine as claimed in claim 1, wherein said slot extending axially of said rotor is rectangularly shaped, and

said shaft has at least a portion thereof substantially equal in width to the height of said slot so as to be slidably received within said slot,

whereby said rotor rotates directly with said shaft and is adapted to shift rectilinearly relative thereto.

4. A rotary internal combustion engine as claimed in claim 1, wherein said housing includes a first end wall closing one end of said cavity;

said valved inlet and exhaust port means open into said cavity through said first end wall; and

said valved inlet and exhaust port means are disposed in a plane extending parallel to the axis of rotation of said shaft and are disposed on the side of said axis remote from the center of said cavity.

5. The combination of claim 4 wherein the vertices of said rotor are each registrable with said port means for closing the ends thereof opening into said cavity.

6. The combination of claim 5 wherein said motor includes mechanical valve means operatively associated with said port means remote from said cavity and valve actuator means operative to open and close said valve means in timed operation in response to rotation of said shaft relative to said housing.

7. The combination of claim 6 wherein said valve actuator means includes oscillatably supported rocker arm means and cam means mounted on said shaft exteriorly of one end of said housing, said rocker arm means including follower portions thereof guidingly engaged with said cam means for oscillation of said rocker arm means in response to rotation of said shaft and cam means, said valve means comprising poppet valves reciprocately supported from said casing, said rocker arm means being operatively connected to said poppet valves for reciprocation of the latter in response to oscillation of said rocker arm means.

8. The combination of claim 7 wherein said cam means comprises a generally cylindrical cam body mounted concentrically on said shaft and including axially spaced grooves extending circumferentially about said cam body said grooves connected by axially inclined ramp defining and peripherally extending groove portions.

9. The combination of claim 1 wherein said rotor and shaft define a rotary assembly, said assembly defining axially extending air passage means extending therethrough with opposite ends communicated with the ambient atmosphere, said assembly including air pump means operatively associated therewith for pumping ambient air through said air passage means in response to rotation of said assembly.

10. The combination of claim 9 wherein said air pump means includes exterior air vanes carried by one axial end portion of said assembly.

11. The combination of claim 9 wherein said rotor includes peripherally extending opposite end groove portions extending along the side faces and at least partially across the opposite ends of said rotor and disposed in a plane generally paralleling the first mentioned plane, and a pair of generally U-shaped seal strips seated in said groove portions and opening toward each other, said strips and rotor including coacting interlocking portions releasably anchoring said strips in said grooves for shifting relative to said rotor in said last mentioned plane generally radially of said axis. 

1. Rotary internal combustion engine including, a hollow housing defining an irregular, generally cylindrically-shaped rotor cavity; a shaft removably journalled for rotation in said housing and extending through said cavity in fixed, offset relation relative to the center of said cavity; said cavity having transverse dimensions which are substantially equal measured along all straight lines extending through the axis of rotation of said shaft; a generally elliptical rotor of fixed transverse dimensions removably mounted on said shaft for direct rotation therewith and also for rectilinear shifting relative to said shaft within said cavity in a plane extending generally through the vertices of said rotor and the axis of rotation of said shaft, the length of said rotor along said plane extending through said vertices thereof being approximately equal to the transverse dimension of said cavity measured through the axis of rotation of said shaft; said shaft mounting said rotor within said cavity so that the opposed surfaces of said rotor extending between the vertices thereof and the irregular shape of the cavity wall continuously define both compression and expansion compartments of predetermined volume varying between minimum and maximum volumes and having a predetermined volumetric relationship to each Other; valved inlet and exhaust port means opening into said cavity for introducing a suitable mixture of air and combustible fuel to said cavity and exhausting said mixture and combustion byproducts therefrom after combustion, respectively; and ignition means mounted in said housing at a point where said compression compartment has its minimum volume, said ignition means creating an electrical spark which is communicated to said cavity for igniting the compressed air and fuel mixture.
 2. A rotary internal combustion engine as claimed in claim 1, wherein said rotor includes a slot extending axially thereof and through which said shaft extends, the medial plane of said slot lying generally upon a line extending between the vertices of said rotor, whereby said rotor is shiftable relative to said shaft in said plane generally radially of the axis of rotation of said shaft.
 3. A rotary internal combustion engine as claimed in claim 1, wherein said slot extending axially of said rotor is rectangularly shaped, and said shaft has at least a portion thereof substantially equal in width to the height of said slot so as to be slidably received within said slot, whereby said rotor rotates directly with said shaft and is adapted to shift rectilinearly relative thereto.
 4. A rotary internal combustion engine as claimed in claim 1, wherein said housing includes a first end wall closing one end of said cavity; said valved inlet and exhaust port means open into said cavity through said first end wall; and said valved inlet and exhaust port means are disposed in a plane extending parallel to the axis of rotation of said shaft and are disposed on the side of said axis remote from the center of said cavity.
 5. The combination of claim 4 wherein the vertices of said rotor are each registrable with said port means for closing the ends thereof opening into said cavity.
 6. The combination of claim 5 wherein said motor includes mechanical valve means operatively associated with said port means remote from said cavity and valve actuator means operative to open and close said valve means in timed operation in response to rotation of said shaft relative to said housing.
 7. The combination of claim 6 wherein said valve actuator means includes oscillatably supported rocker arm means and cam means mounted on said shaft exteriorly of one end of said housing, said rocker arm means including follower portions thereof guidingly engaged with said cam means for oscillation of said rocker arm means in response to rotation of said shaft and cam means, said valve means comprising poppet valves reciprocately supported from said casing, said rocker arm means being operatively connected to said poppet valves for reciprocation of the latter in response to oscillation of said rocker arm means.
 8. The combination of claim 7 wherein said cam means comprises a generally cylindrical cam body mounted concentrically on said shaft and including axially spaced grooves extending circumferentially about said cam body said grooves connected by axially inclined ramp defining and peripherally extending groove portions.
 9. The combination of claim 1 wherein said rotor and shaft define a rotary assembly, said assembly defining axially extending air passage means extending therethrough with opposite ends communicated with the ambient atmosphere, said assembly including air pump means operatively associated therewith for pumping ambient air through said air passage means in response to rotation of said assembly.
 10. The combination of claim 9 wherein said air pump means includes exterior air vanes carried by one axial end portion of said assembly.
 11. The combination of claim 9 wherein said rotor includes peripherally extending opposite end groove portions extending along the side faces and at least partially across the opposite ends of said rotor and disposed in a plane generally paralleling the first mentioned plane, and a pair of genErally U-shaped seal strips seated in said groove portions and opening toward each other, said strips and rotor including coacting interlocking portions releasably anchoring said strips in said grooves for shifting relative to said rotor in said last mentioned plane generally radially of said axis. 